Enamel bonding of single-step self-etch adhesives: influence of surface energy characteristics.

This study examined the surface free energy of enamel treated with the single-step self-etching adhesives Bond Force, Clearfil tri-S Bond and G-Bond. The labial enamel surfaces of bovine mandibular incisors were wet ground with #180-grit, #600-grit and #2000-grit silicon carbide paper. The adhesives were applied to the ground enamel, and then rinsed with acetone and distilled water. The surface free energies were determined by measuring the contact angles of three test liquids placed on the adhesive-treated enamel. The data for each adhesive system were analyzed using analysis of variance and Tukey's honestly significant difference test. The surface free energies of the samples treated with the G-Bond and tri-S Bond adhesives increased as the surface roughness decreased. No significant differences in the surface free energy were found for the samples treated with the Bond Force adhesive regardless of the surface roughness. The results indicated that the surface free energies and their components of the treated enamel surfaces were different among the adhesive systems used.